In the setting of endodontic posts in root canals for support of reconstructions it is important to provide a sanitary environment for the preparation of root canals and following procedures, and equally important to prevent cracking or splitting of the root. This invention relates to a new endodontic reconstruction system which is both therapeutic and protective and atraumatic in use.
Recent years have seen an emphatic surge of using root canal therapy as a means of retaining teeth which otherwise would have to be extracted. Problems of how best to strengthen the endodontically treated tooth to make it a viable component of the mouth are the factors limiting the use of root canal therapy. It is recognized to be a sound, preventive measure to reinforce endodontically treated teeth; and reinforcement is considered mandatory if these teeth are to be crowned or serve as abutments. Preventing fracture is less expensive than replacing a fractured tooth. A pulpless tooth becomes brittle, and use of threaded dowels often fractures the root. A precision fitting dowel has a tendency to exert lateral forces when it is cemented. These problems among others are described in the current literature, of which the following articles are representative:
1. "An endodontic-prosthodontic approach to internal tooth reinforcement"--Sapone and Lorencki--The Journal of Prosthetic Dentistry Vol. 45, No. 2, Feb. 1981, pages 164-174; PA1 2. "In vitro analysis of self-shearing retentive pins"--Collard, Caputo, Standlee, and Duncanson--The Journal of Prosthetic Dentistry Vol. 45, No. 2, Feb. 1981, pages 156-159.
From the standpoint of endodontic practice care must be exercised during mechanical instrumentation if showers of bacteria are not to be forced through the apical foramen. The root canal surface must be thoroughly sterilized and filled if toxic effect upon the periapical tissue is to be prevented. It is recognized that if the root canal surface is rendered sterile and the canal is well-filled, repair of destroyed periapical bone will take place, and the pulpless tooth need not be looked upon as a hazard to health. In order to maintain a sterile operating technique, the rubber dam is used. It is said to be the only sure safeguard against bacterial contamination from saliva. The currently-known practice for using rubber dams is to isolate the entire tooth containing the root canal to be treated, with attendant injury to surrounding gingiva during placement of a clamp for the rubber dam.